Frodo and Sam strike the Road from Durthang to Udûn

They plodded along, on into the night. The hours passed in a weary stumbling trudge with a few brief halts. At the first hint of grey light under... the canopy of shadow they hid themselves again in a dark hollow....

Slowly the light grew.... A strong wind from the West was now driving the fumes of Mordor from the upper airs. Before long the hobbits could make out the shape of the land for some miles about them. The trough between the mountains and the Morgai had steadily dwindled as it climbed upwards, and the inner ridge was now no more than a shelf in the steep faces of the Ephel Dúath; but to the east it fell as sheerly as ever down into Gorgoroth. Ahead the water-course came to an end in broken steps of rock; for out from the main range there sprang a high barren spur, thrusting eastward like a wall. To meet it there stretched out from the... northern range of Ered Lithui a long jutting arm; and between the ends there was a narrow gap: Carach Angren, the Isenmouthe, beyond which lay the deep dale of Udûn. In that dale behind the Morannon were the tunnels and deep armouries that the servants of Mordor had made for the defence of the Black Gate of their land; and there now their Lord was gathering in haste great forces to meet the onslaught of the Captains of the West. Upon the out-thrust spurs forts and towers were built...; and all across the gap an earth-wall had been raised, and a deep trench delved that could be crossed only by a single bridge.

A few miles north, high up... where the western spur branched away from the main range, stood the old castle of Durthang, now one of the many orc-holds that clustered about the dale of Udûn. A road... came winding down from it, until only a mile or two from where the hobbits lay it turned east and ran along a shelf cut in the side of the spur, and so went down into the plain, and on to the Isenmouthe.

To the hobbits... it seemed that all their journey north had been useless. The plain to their right was dim and smoky, and they could see there neither camps nor troops moving; but all that region was under the vigilance of the forts of Carach Angren.

'We have come to a dead end, Sam,' said Frodo. 'If we go on, we shall only come up to that orc-tower, but the only road to take is that road that comes down from it — unless we go back. We can't climb up westward, or climb down eastward.'

'Then we must take the road, Mr. Frodo,' said Sam. 'We must take it and chance our luck, if there is any luck in Mordor. We might as well give ourselves up as wander about any more.... Our food won't last. We've got to make a dash for it!'

'All right, Sam,' said Frodo. 'Lead me! As long as you've got any hope left. Mine is gone. But I can't dash, Sam. I'll just plod along after you.'....

Mordor-dark had returned, and the watch-fires on the heights burned fierce and red, when the hobbits set out again on the most dangerous stage of all their journey. They went first to the little spring, and then climbing warily up they came to the road at the point where it swung east towards the Isenmouthe twenty miles away. It was not a broad road, and... as it ran on the sheer drop from its brink became deeper and deeper. The hobbits could hear no movements, and after listening for a while they set off eastward at a steady pace.

After doing some twelve miles, they halted. A short way back the road had bent a little northward and the stretch that they had passed over was now screened from sight. This proved disastrous.